Superconducting Quantum Interference at the Atomic Scale
| Autor: | Karan, S., Huang, H., Padurariu, C., Kubala, B., Theiler, A., Black-Schaffer, A., Morrás, G., Yeyati, A. Levy, Cuevas, J. C., Ankerhold, J., Kern, K., Ast, C. R. |
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| Rok vydání: | 2021 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/s41567-022-01644-6 |
| Popis: | A single spin in a Josephson junction can reverse the flow of the supercurrent. At mesoscopic length scales, such $\pi$-junctions are employed in various instances from finding the pairing symmetry to quantum computing. In Yu-Shiba-Rusinov (YSR) states, the atomic scale counterpart of a single spin in a superconducting tunnel junction, the supercurrent reversal so far has remained elusive. Using scanning tunneling microscopy (STM), we demonstrate such a 0 to $\pi$ transition of a Josephson junction through a YSR state as we continuously change the impurity-superconductor coupling. We detect the sign change in the critical current by exploiting a second transport channel as reference in analogy to a superconducting quantum interference device (SQUID), which provides the STM with the required phase sensitivity. The measured change in the Josephson current is a signature of the quantum phase transition and allows its characterization with unprecedented resolution. Comment: 10 pages, 6 figures, including supplementary information |
| Databáze: | arXiv |
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